The threads
table provides information about
threads running in the NDB
kernel.
The threads
table contains the following
columns:
node_id
ID of the node where the thread is running
thr_no
Thread ID (specific to this node)
thread_name
Thread name (type of thread)
thread_description
Thread (type) description
Notes
Sample output from a 2-node example cluster, including thread descriptions, is shown here:
mysql> SELECT * FROM threads;
+---------+--------+-------------+------------------------------------------------------------------+
| node_id | thr_no | thread_name | thread_description |
+---------+--------+-------------+------------------------------------------------------------------+
| 5 | 0 | main | main thread, schema and distribution handling |
| 5 | 1 | rep | rep thread, asynch replication and proxy block handling |
| 5 | 2 | ldm | ldm thread, handling a set of data partitions |
| 5 | 3 | recv | receive thread, performing receive and polling for new receives |
| 6 | 0 | main | main thread, schema and distribution handling |
| 6 | 1 | rep | rep thread, asynch replication and proxy block handling |
| 6 | 2 | ldm | ldm thread, handling a set of data partitions |
| 6 | 3 | recv | receive thread, performing receive and polling for new receives |
+---------+--------+-------------+------------------------------------------------------------------+
8 rows in set (0.01 sec)
It is also possible to set either of the
ThreadConfig
arguments
main
or rep
to 0 while
keeping the other at 1, in which case the thread name is
main_rep
and its description is main
and rep thread, schema, distribution, proxy block and asynch
replication handling
. You can also set both
main
and rep
to 0, in
which case the name of the resulting thread is shown in this
table as main_rep_recv
, and its description
is main, rep and recv thread, schema, distribution,
proxy block and asynch replication handling and handling receive
and polling for new receives
.